The present invention relates to a device for treating pneumothorax and pneumohemothorax. Pneumothorax is the accumulation of air or gas in the pleural space which houses the lungs. A pneumohemothorax is the accumulation of air and blood in the pleural space. Either may occur spontaneously as the result of trauma or through a pathological process.
The pleural space is the cavity in the thorax within which the lungs are retained. When we breathe in, our muscles cause the chest walls to move up and out and our diaphragm at the lower portion of the thorax to move down. The lungs, being exposed to greater atmospheric pressure through airways to the mouth or nose, expand with air to fill the increasing volume and equalize the pressure difference. When a person breathes out, the chest walls move down and in and the diaphragm moves up which squeezes the lungs and forces air from the lungs through the airways. The lungs, maintained in the pleural space expand in response to the partial vacuum created when the chest wall moves out and the diaphragm moves down. If the partial vacuum is released or broken, the forces maintaining the lungs in an expanded position are broken and the lung collapses.
Trauma to the chest area such as through a gun shot or knife wound allows air and fluid to enter the pleural space and breaks or releases the partial vacuum therein. The presence of air and fluid in the pleural space prevents expansion of the lung therein. In some cases, the wound acts as a one-way valve allowing air to be pulled into the pleural space as the chest cavity expands, but prevents air from escaping when the diaphragm raises and the chest cavity contracts. If the partial vacuum is not restored to the pleural cavities and the air and fluid therein removed, pneumothorax or pneumohemothorax can be fatal.
Treatment of pneumothorax or pneumohemothorax generally involves patching the wound and then removing the entrapped air or fluid from the pleural space. In hospitals, the air is removed by surgically inserting a tube into the pleural space through an incision between ribs. The tube is then connected to a vacuum source for evacuating the space or the tube is connected to a one-way valve which allows air or fluid to exit the pleural space, but prevents the air or fluid from re-entering as the chest cavity expands and contracts through normal breathing.
When treating pneumothorax or pneumohemothorax in the field, emergency medical technicians, paramedics or the like, typically do not have time to surgically insert a tube into the pleural space. Instead, the emergency care provider will insert a large bore needle or catheter into the pleural space. Prior to insertion of the needle or catheter, the emergency care provider will use the fingertip of a rubber glove to form a one-way valve on the end of the catheter. The finger-tip is cut from a glove and the needle or catheter inserted through the end thereof, such that the open end of the finger-tip extends past the end of the needle or catheter. When the chest cavity contracts during exhalation, air is forced through the needle or catheter and past the rubber glove fingertip. During inhalation as the chest cavity expands to create a partial vacuum, the partial vacuum cause the sides of the rubber glove fingertip to collapses preventing air from entering the pleural space. The main drawbacks to the fingertip one-way valve arrangement are the time it takes to make the one-way valve, by cutting the fingertip and inserting the needle therethrough and the inability of the fingertip one-way valve to consistently form a good seal.
U.S. Pat. No. 4,813,941 discloses a pneumothorax treatment device comprising a one-way valve having a luer lock receiving adaptor secured thereto, such that the one-way valve can be quickly connected to standard needles and catheters incorporating luer lock lugs. In the field, the emergency care providers simply inserts the needle or catheter into the pleural space, then connects a pre-formed one-way valve thereto using the luer lock adaptor such that the one-way valve may be rapidly connected to the luer lock connecting lugs of standard catheters. Although an improvement over the rubber glove fingertip one-way valve, this device does have its limitations. In particular, the device is difficult to secure to a patient during transportation, the device is not adaptable to be hooked up to a suction device and the valve is prone to sticking due to blood and other fluids entering the valve body and drying.